I got this system up and running a few days ago after receiving the rl 1.5's. I was using the the rest of the components for about a month with some mid-fi bookshelf speakers. Initial impressions were that the speakers imaged well and the tone was a bit on the warm side. Bass, while lacking just a bit, sounded very real.

I spent a couple of days experimenting with speaker placement and letting the speakers break in a bit. Now I was hearing sounds coming from above, behind, and beyond the speakers. I realized why the bass seemed so real. Regardless of what the room nodes are doing to the bass, you can always feel the bass thanks to the bottom-firing passive radiator. There is a basement below me and I'm sure that helps.

Things were really starting to sound good after a couple of days, but some vocals seemed just slightly muffled, as if a bit too pronounced in the midrange and the sound was a little too warm in general. I tried lowering the value of the tweeter resistor (which was 6 ohm), and that helped with the overall frequency balance, but I realized the crossover point was too high to help with the vocal issue. I decided out of curiosity to measure the frequency balance at my listening spot using 2/3 octave filtered pink noise. I wasn't surprised to find a smooth peak centered at about 1K. I imagine this might change somewhat as the driver breaks in but to what extent I don't know. Just for fun I punched the corrective values into a 2/3 octave linear-phase EQ that I found online as freeware. I am using it as a VST plugin with Winamp media player. The speakers really didn't need much in the way of correction and I want to stress that things were sounding very good at this point even without it, but it was about to get even better.

Now with the eq running and some more burn-in time, I'm hearing incredible depth, width, height, speed, timbre, and with perfect frequency balance! Maybe eventually I will lose the desire to use the eq plugin but right now it sounds so incredible I just want to stop fooling around a listen to music.With my eyes closed, these speakers completely dissapear with certain recordings and I am transported to the recording location. The bass is wonderful and I have no desire to fuss with a sub. It's not the loudest system, but even when set so as to never clip, it's plenty loud for my taste. And that's with about a 2db average loss due to the use of the eq (I only made cuts and didn't apply any makeup gain to ensure no clipping at any frequencies). I can't express in words how enjoyable this system is. It makes stunningly beautiful music and I couldn't be happier.

Well, thanks so much for sharing your impressions! Welcome to the Radial club! I've never heard the 1.5s, maybe one day soon enough, but I have had RL2s for years and just love them.

Oddly I've had some not muffled necessarily but recessed sounding vocals at times, and that's one way I seem to be able to distinguish that my power tubes are getting low; when replaced with new tubes the situation is ameliorated.

I Just wanted to do an update to my initial review. It's been a couple of weeks now, and the sound has relaxed further. The response has really flattened out to the point where using an eq plugin is unnecessary. Subsequent measurements confirmed what my ears told me. I didn't expect quite so much of a change. Also I put the factory installed 6 ohm resistor back on the tweeter posts. I am growing to appreciate the warmer tonality now. The sound is so natural it's ridiculous. Anyone wanting a natural and spacious musical presentation needs to hear these speakers. Of course I'm extremely happy with the Altmann components as well. Hope this has helped. --Greg

I have had a pair of Radial 1.5s for about a year now. They were originally owned by Steve Deckert as RL2.0s. They have been since upgraded to 1.5s and were basically "new" when I received them. I absolutely love them. Without getting technical, I can never imagine myself listening to non-radial speakers ever again. Congrats on your 1.5s and enjoy. :)

I actually made the files myself by using the eq (LPEQ) in conjunction with my sound editing software (cakewalk sonar) and a pink noise wav file. Then it dawned on me that I probably should have used white noise, but it seemed to have still worked pretty well.

Anyway, I imported the noise file into sonar and used the eq as an effect plugin. One by one I raised each individual slider up 24db, adjusted the gain and created new wav files to correspond with each eq band. I also used a touch of limiting on each track for more consistency. Then I placed a condeser mic in front of one of the speakers, played the new test tracks, and compared the level of each track using Sonar's level meter. At that point you have your corrective values and you're done. I think it's great that I was able to use the same eq with Sonar and Winamp so the test tracks were made with the same filters as the corrective device uses. Only downside is I can't do independent channel correction with this particular EQ but I'm happy with it right now. Pink noise played through the speakers with the eq now sounds more neutral and closer to what I hear with my sennheiser headphones.

Anyway I'll be happy to share my test tracks if you think they are close enough to what you need. --Greg

At this point though, I think I'm through using any eq at all. It was helpful when the drivers were stiff but now the sound is just more pleasing without any "correction". It seems with this level of resolution, any corruption to the signal is objectionable. The sound quality just degrades in direct proportion to the level of correction used. The worst sound I achieved was with room correction software. I ran it with a close proximity mic and the corrected sound was just awful. I won't even mention the results I got when the mic was in the listening spot. Anyway I absolutely love the radials and anyone skeptical about digital or solid state should hear this rig.